Ice thickness control



Mayt17, 1966 H. R. GUETSCHOW ICE THICKNESS CONTROL Filed May 13, 1964 INVENTOR. fi gazzei c l ow' 'perature thus changing the cycle of operation.

United States Patent 3,251,195 ICE THICKNES CONTROL Harold R. Guetschow, RED. 1, Box 138, South Beloit, llll. Filed May 13, 1964, so. No. 367,139 8 Claims. (Cl. 62-139) This invention relates to an ice thickness control system and apparatus for a plate type of ice making machine.

One form of an ice cube maker that is in general use today employs a freezing plate which is somewhat inclined. Water flows onto the high side of the plate and freezes on the plate forming a layer of ice. When the ice builds up to the desired depth, a thickness control senses that fact and signals a change in the cycle. At the time of this change the plate is warmed to defrost it and break the bond between it and the sheet of ice. The sheet of ice slides off the low side of the plate and onto an apparatus whichcuts the sheet of ice into cubes. A common form of such cutting apparatus is an electrically heated Wire grid. The heated wires cut the sheet of ice into cubes which then fall through the grid into a tray I below the grid.

There are two general forms of ice thickness controls being employed to measure the depth of the ice on the plate and thus signal the start of the change of the cycle. One of these is thermostatically operated. A wafer thermostat is positioned to be contacted by the ice when it reaches a given depth. By sensing the change in temperature as ice reaches the wafer, an electrical signal is produced. Such devices have the disadvantage that over a period of time a layer of lime will deposit on the wafer from the water. How fast this occurs, of course, depends upon the hardness of the water. However, when it does occur, it changes the sensitivity of the thermostat. Furthermore, such a thermostat warms up slowly after the ice has left the plate-with the result that a recycling may not start as rapidly as would otherwise be possible. Obviously, such a thermostat is subject to changes in ambient tem- Such devices can drift and get out of adjustment with the necessity of being serviced.

A second form of commonly used control is a mechanical feeler. One such fecler isa cam rotating about an axis. As the cam contacts ice of the desired thickness, the axis of rotation of the cam is shifted sideways away from the ice, thereby actuating a switch. Such controls are more trouble free than are the thermostatic type. However, it includes a number of working parts that are eliminated by the present invention.

The present invention is extremely simple. It is posi tive in operation. Even if lime were to build up on it, the cycling of the cube making apparatus would not be materially changed. It is trouble free, having little to get out of order. It can be readily and quickly adjusted for desired changes in the thickness of the sheet of ice, and thus the thickness of the cubes.

Embodiments can be made which serve as a check on whether or not the sheet of ice has fully left the freezer plate. Occasionally, with prior art devices, the sheet of ice would only partially leave the freezer plate and pass only partially onto the -grid. The result would be that water would build up on the freezer plate and overflow all about the ice cube making apparatus.

Other objects of the invention will be described in the specification, and will be more apparent from the accompanying drawings, in which:

FIGURE 1 is a fragmentary perspective view of one embodiment of the invention; and

showing a second embodiment of the invention.

3,251,195 Patented May 17, 1966 Although the following disclosure offered for public dissemination is detailed to ensure adequacy and aid understanding, this is not intended to prejudice that purpose of a patent which is to cover each new inventive concept therein no matter how others may later disguise it by Prior art ice maker Referring now more particulary to FIGURE 1 of the drawings, a freezing tray or plate 10 has opposite raised sides 12, 14 and an end 16. A horizontal water header 18 extends across the high side of plate 10 and has water outlet holes 20 to distribute an even flow of water over the freezing plate. Water is pumped from a supply tank 22 below the plate by means of a pump in the tank and through a hose 24 connected to the header 18. The plate end opposite the header 18 has no upright wall but is formed with a downwardly curved edge .26. Plate 10 is inclined downwardly from theheader 13 to edge 26.

Below plate ll) and in intimate association therewith are the freezing coils of a refrigeration apparatus (not shown). This apparatus maintains plate 10 at a temperature at which the water released from openings 20 will freeze on the plate. A sheet of ice forms on plate It) and gradually increases in thickness.

Below the curved edge 26 is a water tray 28 having a bottom discharge pipe 30 leading to the supply tank 22 and a downwardly curved discharge edge 32 which may be slightly in advance of the plate curved edge 26. Surplus water drips from the plate 10 and is thus conducted back to the tank 22. V

One edge of an ice cutting grid 34 is located closely below the curved edge 32 of the water tray 2% and also closely below the plate edge 26. Grid 34 comprises an open rectangular frame with transverse grid. wires 36 and 38 extending between relatively opposite sides. These wires are connected into an electrical circuit so that they can be electrically heated to cut a sheet of ice into smaller pieces which then fall through the grid 34.

Directly below the grid 34 is the cut ice holder 40 having a water drain 41. A siphon tube 42 extends from the supply tank 22 to drain 4].. When tank 22 fills due to shutting off the pump, the siphon acts to clean the receptacle of any sediment which may have settled therein.

Ice thickness control of this invention At one side of the freezing tray 10 is a conduit in the form of an open water trough 44 with a scoop 46 at the end thereof adjacent the header l8. Scoop 46 is above A the top of plate 18. Trough 44 has a spout 48 at the other lower end. When the ice on plate 10 builds up to the desired thickness, scoop 46 receives water flowing over the top of the ice on plate 10 from openings 20. An adjusting screw 52 supports mounting bracket on side 12 to permit the scope 46 to be raised and lowered to vary the ice thickness. At the spout end the trough 44 is pivotally supported by a second bracket 54 secured to a wall 56 adjacent to the apparatus. Bracket 54 is positioned so that at all adjustments of screw 52 the trough 44 slopes downwardly toward spout 48.

Also attached to the wall 56 is a water pan 58. One side of pan 58 is secured by a pivot 60 to the wall 56. A leg 62 extends downward from the opposite end. Spout 48 is located to discharge water freely into the pan 58. An.

electric snap-action switch 64 has a contact arm 66 extending outwardly for engagement with an actuating arm 68 on the pan 58. The portion of pan 58 to the left of pivot 60 is deeper than that to the right of pivot 60. Thus water discharged into the pan will cause it to be filled with more Water at the back and tilted downwardly at the back with the leg 62 upwardly. The tilting of pan 58 is arrested by pan arm 68 contacting actuating arm 66. Switch 58, when actuated, closes a circuit (not shown) for defrosting plate 10, heating the wires 36 and 38, and stopping the water circulation pump.

Upon the defrosting action of plate the ice thereon, which is of the proper thickness, slides from the plate 10 and onto the grid 34. Projecting leg 62 is contacted by ice moving onto the grid wires 36 and 38 and the ice tips pan 58 to spill the water from the front of the pan 58. As this occurs, arm 68 moves away from switch contact arm 66 to recycle the apparatus for a repetition of the complete action.

In the embodiment of FIGURE 2 a short trough '70 has an intermediate supporting bracket '72. An adjusting screw 74 connects bracket 72 to the side 12 of freezing plate 10. At the front end of the trough is a scoop 76 for picking up water from the surface of the ice after the ice attains a predetermined thickness. At the rear end trough 70 is connected by a hinge '78 to the front end of a flat pan 80. A rear beveled end 82 of pan 80 forms a spout. A pivot rod 84 extends from the adjacent side 12 to pivotally support pan 80. Rod 84 is secured to the pan and pivotally connected to the side 12. It will be noted that the pivotal axis of rod 80 is off center on pan 80 and adjacent the hinge 78 rather than spout 82. An adjustable counterweight 86 extends rearwardly from the pan 80 and serves to keep the rear end of pan 80 down and its front end up.

An electric switch 88 is mounted on the plate side 12 and has a projecting contact arm 90. Pan 80 has an arm 92 on pivot rod 84 to engage the contact arm 90 of the switch to change electrical connections (not shown) to the defrosting means, etc.

With the construction of FIGURE 2 the ice builds up in thicknes until the water runs from the top of the ice into scoop 76. From scoop 76 the water runs through the trough 70 into the pan 80. Pan 80 tilts slightly downwardly at end 82, but after only a slight tilt it comes to rest against the ice slab formed below it. At the same time arm 92 of the pan releases the contact arm 90 of the switch 88. Switch 88 starts plate 10 to defrost, energizes grid 34 and stops the pump in tank 22.

When plate 10 defrosts, the ice thereon slides down onto the grid 34. Since water pan 80 was resting on the ice, it was held substantially upright, holding the water in it.

. But as soon as the ice moves onto the grid 34, the spout end of the pan 80 tilts downwardly, emptying the water from the pan. The counterweight 86 then returns the pan to original or empty position. Arm 92 engages the contact arm 90 of the electric switch 88 returning the switch to its original position and recycling the apparatus.

In these two embodiments of the invention the action is substantially the same. When the ice builds up to the desired thickness, water from the surface thereof is picked build up ice thickness thereon, the improvement comprising: a movably mounted water pan means, a water scoop mounted a given distance above said plate to receive water from the top of the ice, conduit means leading from the scoop and discharging into the pan means to move the pan means, an electric switch operatively connected to the pan means to be actuated by the movement of the pan means to defrost the plate, and means connected to the pan means and responsive to the ice leaving the plate to empty the pan means and reset the switch.

2. An ice thickness control system according to claim 1, in which the water pan means is pivotally mounted and is positioned to be engaged by the ice in its movement from the plate to tilt the pan means and to discharge the water from the pan means.

3. An ice thickness control system and apparatus according to claim 2, in which an ice melting grid is located at the low side of the freezing plate to receive a sheet of ice of predetermined thickness and substantially the area of the plate, the tilting pan means being located selectively at the side of the grid for actual contact with the first of the ice near the end of the grid to discharge the water.

4. In an ice cube making apparatus including an inclined freezing plate onto the high side of which water is discharged for building up a sheet of ice on the plate and having a cutting grid below the low side of the plate, and an ice thickness control signal means to defrost the plate when the ice reaches a predetermined thickness so that the ice slides onto the grid to be cut into cubes, the improvement comprising: said ice thickness control means including a water scoop positioned above said plate a distance such that water will flow from the ice onto the scoop when the ice reaches the desired thickness; and actuating means including a switch and communicating with the said scoop to receive the Water and to produce an electrical signal.

5. In an apparatus as set forth in claim 4 wherein said actuating means includes a pivotally mounted water pan operatively connected to the switch, said pan having means to receive said water from the scoop and direct it into the pan, said pan being adapted to be pivotally unbalanced by the water therein to pivot the pan sufficiently to actuate the switch.

6. In an apparatus as set forth in claim 5 wherein the volume of the pan at one side of the pivotal mounting is greater than the volume at the other side of the pan.

7. In an apparatus as set forth in claim 5 wherein the pan is so positioned that a part of the pan is supported on the ice and prevents the pan from spilling when it is filled with water until the ice moves from under said part and permits the pan to tip and empty.

8. In an apparatus as set forth in claim 5 wherein the sheet of ice moving from the plate to the cutting grid moves along a predetermined path, said pan having means positioned in said path and effective to pivot the pan sufficiently to empty it when said pan means is contacted by the sheet of ice moving from said plate to said grid.

References Cited by the Examiner UNITED STATES PATENTS 6/1954 Ayres et al 62138 X 10/1954 Andrews. 

1. IN AN ICE THICKNESS CONTROL APPARATUS WITH AN INCLINED FREEZING PLATE HAVING A WATER HEADER AT ONE END TO BUILD UP ICE THICKNESS THEREON, THE IMPROVEMENT COMPRISING: A MOVABLY MOUNTED WATER PAN MEANS, A WATER SCOOP MOUNTED A GIVEN DISTANCE ABOVE SAID PLATE TO RECEIVE WATER FROM THE TOP OF THE ICE, CONDUIT MEANS LEADING FROM THE SCOOP AND DISCHARGING INTO THE PAN MEANS TO MOVE THE PAN MEANS, AN ELECTRIC SWITCH OPERATIVELY CONNECTED TO THE PAN MEANS TO BE ACTUATED BY THE MOVEMENT OF THE PAN 